Relocate my followers to my Whiterun home?

Lydia is the only follower, aside from someone you marry (all mercenaries, housecarls, Companions and about half of the other potential followers), whom you can "relocate" to Whiterun. That is, she's your housecarl in Whiterun, so that's kind of where she's supposed to be.

However, if you want to keep several followers in one place, one option is to recruit some followers to the Blades after you've progressed far enough in the main quest. Most followers can become Blades. Once they've been inducted, they'll all relocate to Sky Haven Temple. Also, if you complete the Companions quest line, you will have seven more potential followers in Jorrvaskr, which is just down the road from Breezehome in Whiterun.

Note that if you tell a follower to wait in Whiterun, a) you won't be able to recruit another follower, and b) after a few in-game days that follower will return to his/her original location.

You can't "re-home" npcs... but you could if you wanted to.

As brymck explains, in the default game only Lydia chooses Breezehome as her home. However, if you wanted to change that, and if you're into mods, the mod My Home is Your Home by Volek might be exactly what you want.

The mod's description reads:

Features:

• You can give each of your followers their own home.
• Dismissed followers will return to their new home.
• The new home can be any place, including custom player homes.
• They will wander around, eat, sleep, use furniture and tools.
• You can assign guard/sleep/work areas for up to 60 followers. The assigned area can be anywhere, they will change locations to reach it.
• You can fast-travel to any follower's home if you talk to them while they are following.
• Compatible with Ultimate Follower Overhaul, Amazing Follower Tweaks, Simple Multiple Followers, Spouses Can Live Everywhere and Extensible Follower Framework.
• Supports up to 250 followers.
• Supports custom followers.

This mod is available on Nexus for Oldrim by Volek and for SSE uploaded^* by FakeTails and is available on BethesdaNet for XBox ported and uploaded by Allie1718.

^* I'm very confused in reading the upload who ported it and who uploaded it.... so I might have that wrong. Looks like Allie1718 did the port and FakeTails just uploaded it to nexus for SSE. I think.